A fossil fuel has very limited reserves, such that it can not but be depleted. Particularly, since the fossil fuel is a main discharging source of greenhouse gas causing global warming, advanced countries have concentrated their efforts on developing alternative energy or hydrogen energy using nuclear power in order to decrease the fossil fuel. As an energy source that has been spotlighted as the alternative energy, there are several energy sources such as solar energy, wind power, hydrogen energy, biomass, and the like. In the case of solar heat or wind power, an auxiliary device should be provided, a wide space is required in order to install a heat collecting plat or a windmill, and other environmental problems such as destruction of an ecosystem, noise, and the like, are generated. The future energy requires requirements such as environmental acceptability, economic productibility, eternal capability, and the like.
A fuel cell, which is a cell directly converting chemical energy generated by oxidation into electric energy, is a new environment-friendly future technology generating the electric energy from materials richly present on Earth, such as hydrogen or oxygen.
In the fuel cell, oxygen is supplied to a cathode and hydrogen is supplied to an anode, such that an electrochemical reaction is performed in a form of a reverse reaction of electrolysis of water to generate electricity, heat, and water, thereby producing electric energy at a high efficiency without generating pollution.
The fuel cell producing the electricity and the heat using a fuel such as city gas, or the like, which is a typical new growth engine industry having a very large job creation effect as well as an effect of decreasing greenhouse gas, has been actively commercialized all over the world.
The fuel cell is mainly satisfactory in that it may produce both of the electricity and the warm water, save electricity and heating expenses, and contribute to prevention of global warming.
When the fuel cell is installed at the home, a consumer may decrease an energy cost and may benefit by a rise in a value of a house due to an environment-friendly feature. The government may have an advantage that a discharge of greenhouse gas may be decreased by 30% or more as compared with an existing power generation scheme. However, in spite of these advantages, a home fuel cell has not been actively popularized domestically. The reason is that awareness of consumers for the fuel cell is low and a product is expensive. Nevertheless, it is undoubted that the fuel cell is required in terms of environment and a broad perspective.
One alternative to an electricity supplying problem of Earth is a renewable distributed energy generator (RDEG) technology. In the RDEG technology, electric power may be produced at a consumption point, and expensive and inefficient transmission and distribution networks may be decreased. In the RDEG technology, greenhouse gas is discharged as small as possible while producing the electric power. This technology provides benefits such as more controls, agility, a cost decrease, and the like, to a customer and has potential power capable of minimizing complexity associated with a centralized energy resource. However, nowadays, economics of the RDEG technology has not secured its position. For this reason, the government directly provides a subsidy in commercialization of the RDEG technology.
The RDEG technology is mainly configured of three technologies. They are a solar light technology, a small wind power technology, and a fuel cell technology. When analyzing an electric power market, the RDEG technology has occupied only a very small portion in all power generation sources.
A stationary fuel cell has a large potential power in the long view. The stationary fuel cell corresponds to a clean and efficient power source and may have a power generation capacity of 1 KW to 10 MW. Through a more reformative technology, the fuel cell may use an existing or accessible fuel such as natural gas or use other fuels including a bio-fuel and gas, which are byproducts of an adjacent industrial process. In the case in which the fuel cell is combined with a combined heat and power plant, efficiency may be significantly increased from about 40 to 50% to about 85%. However, a cost problem makes it difficult to predict a long-term potential power of this technology. In order to decrease the cost, a scale should be increased. However, in order to increase the scale, the cost should be significantly decreased. When a continuous support program of the government is not present, it may not be appreciated whether this technology may arrive at a success critical point and when this technology arrives at the success critical point.
In order to commercialize the stationary fuel cell, there are many problems that are to be solved, such as a method for manufacturing a stationary fuel cell at a reasonable cost, development of a stationary fuel cell system having high efficiency, and the like. Among them, a technology for predicting a quality variable that may not be measured directly by a sensor is required in order to improve stability in operating a fuel cell system and improve performance of the fuel cell system.
In addition, a fuel cell vehicle is the future vehicle using a scheme in which a fuel cell using a chemical reaction between hydrogen and oxygen drives an electric motor, and it is likely that the fuel cell vehicle will play a leading role in the future vehicle industry. An advantage of this technology is to decrease an operation cost by significant improvement of fuel efficiency and expect an air pollution preventing effect by a decrease in exhaust gas.
In order to commercialize the fuel cell vehicle, there are many problems that are to be solved, such as a method for manufacturing a fuel cell vehicle at a reasonable cost, development of a fuel cell system having high efficiency, a technology for obtaining a large amount of hydrogen at a reasonable cost, a safe hydrogen transporting system, a hydrogen storage, a pressing apparatus for charging a vehicle at a reasonable cost, build-up of a hydrogen infrastructure, and the like. Among them, a technology for predicting a quality variable that may not be measured directly by a sensor is required in order to improve stability in operating a fuel cell system and improve performance of the fuel cell system.
US Patent Application Publication No. 2011-0244350 has disclosed a fuel cell system.